Piecemeal cold snare polypectomy was effective and safe for sessile, serrated colon polyps larger than 10 mm in a series from the University of Sydney.
Endoscopic mucosal resection (EMR) is the usual choice for lesions that size, but it comes with the risks of electrocautery, including delayed bleeding in perhaps 10% of patients. The Sydney investigators took a gamble to see if cold snare polypectomy, a technique usually reserved for smaller sessile, serrated polyps (SSPs), worked as well as EMR for larger ones, but without the risks. That seemed to be the case in their pilot study; . The median lesion size was 15 mm, and ranged from 10 to 35 mm. The procedure took a median of 4.5 minutes, much quicker than EMR, and didn’t require submucosal lifting injections. There were no perforations, deep injuries to the colon wall, or intraprocedural bleeding. There were no significant adverse events at 2 weeks, including no delayed bleeding or postpolypectomy syndrome.
Most importantly, there was no evidence of recurrence in the 15 lesions that had surveillance colonoscopy by press time at a median of 6 months. “We suggest, cautiously, that this is related to the wide margin of [normal] tissue [2-3 mm] removed during the initial procedures and the meticulous examination of the defect and margin for residual tissue,” said investigators led by David Tate, MD, of the University of Sydney.
“We have demonstrated the safety and feasibility of pCSP in a tertiary referral cohort of patients referred for the removal of large SSPs. There is potential for pCSP to become the standard of care for nondysplastic SSPs. This could reduce the burden of removing SSPs on patients and health care systems, particularly by avoidance of clinically significant postendoscopic bleeding,” the investigators wrote.
“Because SSPs commonly lack high-grade histology, have a long dwell time prior to developing dysplasia, and recur less frequently than conventional adenomas, they represent comparatively indolent disease and are excellent targets for piecemeal mucosal resection,” the researchers said.
Resection was performed with a stiff thin-wire snare (TeleMed 10-mm hexagonal, TeleMed Systems). “A thin-wire snare is paramount, both to aid tissue capture and to create a crisp resection margin that can be examined for residual serrated tissue. Each progressive resection utilizes this margin to ensure snare purchase and avoid tissue islands,” the researchers said.
It took a median of three cuts to remove an SSP; complete resection was achieved in all cases.
The team used high-definition endoscopic imaging to assess the lesion and margins before the procedure, and again to assess the defect margin to ensure the absence of residual serrated tissue. “We did not use submucosal injection or a chromic dye. While we acknowledge their utility for delineation of serrated tissue, we found that high-definition imaging was sufficient for this purpose and for detecting residual serrated tissue at the resection margin,” they said.
Patients were a mean age of 69 years old; almost 80% were women. About two-thirds of the lesions were proximal to the transverse colon.
The work was supported by the Cancer Institute New South Wales. The investigators had no conflicts of interest.
SOURCE: Tate DJ, et al. Endoscopy. 2017 Nov 23. doi: 10.1055/s-0043-121219.